Filament production monitor

ABSTRACT

A means for monitoring the formation of filaments as they issue from a bushing, spinneret or other orifice source to sense disruption of filament formation as a change in the gas flow and/or thermal conditions in the vicinity of the filament formation means. Thermocouples will sense such changes to issue an actuating signal through suitable amplification means to process monitoring or control equipment.

United States Patent 1 Johnson [111 3,820,967 1 June 28, 1974 [54] FILAMENT PRODUCTION MONITOR [75] Inventor: Charles William Johnson,

Waterville, Ohio [73] Assignee: Johns-Manville Corporation, New

York, NY.

22 Filed: Mar. 5, 1973 21 App]. No.: 338,005

Related US. Application Data [63] Continuation of Ser. No. 102,768, Dec. 30, 1970,

abandoned.

[52] US. Cl 65/2, 19/22, 57/81, 65/11 W, 65/29, 65/158, 242/29 [51] Int. Cl C03b 37/02 [58] Field of Search 65/1, 2, 11 W, 29, 158; 19/.22; 57/81; 226/48; 242/29; 264/40; 55/473 [56] References Cited UNITED STATES PATENTS 3,301,647 1/1967 Shafer 65/2 EVENT RECORDER AND CONTROL 8/1967 Scarpa .1 73/204 7/1970 Maynard ..55/473X Primary Examiner-Robert L. Lindsay, Jr. Attorney, Agent, or Firm-R. M. Krone; J. D. Lister 57 ABSTRACT A means for monitoring the formation of filaments as they issue from a bushing, spinneret or other orifice source to sense disruption of filament formation as a change in the gas flow and/or thermal conditions in the vicinity of the filament formation means. Thermocouples will sense such changes to issue an actuating signal through suitable amplification means to process monitoring or control equipment.

3 Claims, 2 Drawing Figures BREAK- OUT INDICATOR EVENT RECORDER PROGRAMMER AND CONTROL FIG.I

INVENTOR. CHARLES WIILLIAM JOHNSON ATTO R N EYS BACKGROUND OF THE INVENTION Heretofore monitoring of filament production has required continuous observation by personnel of the apparatus from which the filaments issue. Such observation is expensive in observer time consumed and often is a task performed with substantial discomfort and inconvenience due to the location of the filament issuing station.

Frequently, it is desirable to coordinate the instant of disruption in filament production with changes which occur in other phases of the process which may be located in a remote location from the filament issuing station. Such coordination is difficult and may require a second observer and/or communication means between the monitoring stations.

Asparticularly applied to the production of glass fila ments as textile strands, continuous surveillance of the bushings from which the filaments issue and the winders upon which the strands of gathered filaments are wound isemployed to evaluate the plant operation. Factorsascertained include the length of time the bushing ran, the length of time the winder ran, the interval betweenfilament breakout and stoppage of the winder. These factors are employed to determine bushing performance in terms of individual and average run times, to determine service time as the changing of winder tubes and restart of the unit, and to check yardage.

SUMMARY OF THE INVENTION The present invention relates to filament production and more particularly to means for monitoring the formation of filaments and for utilization of the signals indicating filament production and interruption of such production.

In one embodiment the invention comprises means sensing the flow of gas in the vicinity of the orifices from which filaments issue, In the case of glass filaments such sensing is by means of a thermocouple located near the path of the filaments. It has been observed that air is aspirated by the drawing of the filaments along their normal path toward the apparatus for subsequent processing of the filaments, such that an increase in temperature is experienced when the drawing of the filaments is interrupted. A thermocouple mounted about one-eighth inch below the tips issuing filaments from the orifices and about one-eighth inch outward from the outermost filaments will respond to such temperature changeswith a readily detectable signal almost immediately following the disruption.

The signals from the thermocouple are passed through a suitable amplifier in which they are calibrated for the operating temperatures of interest and from which they are applied to suitable indicators, controls, recorders, or combinations thereof. One utilization in monitoring plant efficiency is to apply the signal indicating a breakout of the filaments on one channel of an event recorder while the control for the winder for those filaments is applied to another channel of the event recorder to indicate the delay in changing winding tubes and restarting the winder following a breakout. Another control might include application of a winding signal to the programmer for the system to terminate the winding when the interval of winding has been maintained for the yardage desired. An automatic cutoff for the winder can be actuated by a signal from the detector as soon as filament formation is disrupted, thereby eliminating the possibility of an operator inadvertently catching hanging fiber in a moving traverse while manipulating fiber for winding.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a frontal schematic view of apparatus for producing strand packages illustrating the positioning of thermocouple sensors adjacent bushing tips from which filaments making up two strands are drawn together with schematic electrical controls utilizing the thermocouple signals according to this invention; and

FIG. 2 is a sectioned and broken side view taken at 2-2 of FIG. 1 of a bushing with a thermocouple located adjacent a filament array and including a diagrammatic representation of the air flow induced by the traveling filaments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may be used in the formation of filaments from any of a number of materials such asdisruption of such condition. While other means for measuring gas flow in the vicinity of moving filaments maybe employed, where thermal differences occur between the relatively static mass of gas when no filament motion is present and the flowing gas induced by the motion of filaments, a thermocouple has been found satisfactory as a sensor when coupled to a suitable amplifier.

A portion of a receptacle 10, a bushing, adapted to contain a supply of molten glass and having a plurality of small apertures or orifices 11 in its bottom is shown in FIGS. 1 and 2. An extension or tip 12 surrounds each orifice as best seen in FIG. 2. Filaments 12 are exuded through orifices 11 as molten streams of glass which can be impelled therefrom by gravity and as they solidify they are drawn downwardly at high speed by winding equipment.

In the example, two groups of filaments 13 which may comprise hundreds of filaments are first brought together by grooved spools l4 functioning to cause the convergence of the filaments into four subgroups 15 by guiding them in parallelism along grooves 16. A dressing which is in liquid form and can be a binder, lubricant, coupling agent or combination thereof is applied at a coating station either as a spray or by wiping the filaments on a felt pad 17 saturated with the dressing or a transfer roll (not shown) preceding the converger l4. Substrands 15 can then be gathered to a strand 18 by grooved spool 19 and carried to a traversing mechanism 21 and thence to a winding tube 22 mounted on collet 23. 7

Two strands 18 are wound into packages 20 simultaneously hence each has a traverse 21 and a winding tube 22 on collet 23. In winding a strand is secured to collet 23, and collet 23 is started in rotation by means of motor 24 as energized through programmer and motor control 25. A given interval after the initiation of collet rotation, the programmer 25 starts traverse motor 26 and mandrel reciprocation drive 27. The traverse 21 developes a pattern of strand motion within a range of positions defined by its camming form 28. This pattern complements the reciprocation of the carriage 29 upon which winding collet 23 and motor 24 are mounted for motion along ways 30 as shown by arrow A.

A correlation between the winding stop and startup operations and the drawing of filaments from tips 12 is a significant measure of filament production. That is an excessive delay between the bead out or disruption of filaments issuing from tips 12 and the termination of winding indicates either an inattentive or over burdened attendant or some other condition creating excessive down time and loss of production.

Filaments issue from orifices 11 and are drawn at speeds of from about 5,000 to l5,000 feet per minute by the rotation of collet 23. At these speeds the fibers are attenuated to a substantial degree while in a viscous state and a relatively small volume of glass is retained in the meniscus 31 at tip 12 as illustrated in FIG. 2. The high speed of the filaments 13 and their relatively close spacing induces a flow of the ambient gas, air in the case of glass filament formation process illustrated, as best illustrated in FIG. 2. In practice tips 12 are arrayed in paired ranks and are spaced about a tenth of an inch on centers with the tips of the inner rank slightly offset from those of the outer rank so that the filaments form a downwardly moving curtain. The air aspirated by that moving curtain flows along the path of the labeled arrows in FIG. 2 and thereby removes a substantial amount of heat radiated from the bottom of the bushing and the issuing glass, changes in temperature attributable to this phenomenon are utilized in the process of detecting disruptions in filament motion.

Typically an 800 tip bushing will be employed to produce eight one hundred filament substrands which are converged to two 400 filament strands 18 for winding. While air will be aspirated by a single filament, as a practical matter in industrial processing conditions the differential in temperature realized from the air flow induced by travel of a single filament requires a sensor of extreme sensitivity which can be actuated by changes in ambient condition which are not indicative of filament motion. Accordingly, significant changes in air flow are best realized within the vicinity of groups of filaments. For example, a group of about 100 filaments spaced on about one tenth inch centers drawn at temperatures above 2,000F at a rate of between 5 and 15,000 feet per minute will aspirate sufficient air from an environment of below l00F to reduce the temperature sensed one-eighth inch from the outer layer of a group of filaments and one eighth inch below the tips issuing those filaments by between l0OF and 200F below that present at that location when the group of filaments is stationary as where they have broken out and drawing has ceased.

Typically a disruption in the drawing of the planar arrays of filaments 13 issuing from tips 12 occurs as a rupture of one or a few filaments which then flow under the head of molten glass 40 as relatively thick filaments which have sufficient motion within the array to inter rupt or snip off adjacent filaments. This interruption progresses throughout the array, frequently resulting in the merging of several broken filaments to form beads of glass, hence the term head out as applied to such disruptions. Upon the termination of all filaments making up a strand, the winder ordinarily is stopped, the winding forms 22 removed, new forms 22 are mounted on the collet 23 and the broke filaments collected for reinsertion into the convergers 14 and 19 and connection to the collet 23 or winding forms 22. The collet is then placed in rotation after which the traverse and reciprocating drive are actuated.

Chromel-alumel thermocouples 32 are illustrated as sensors centered on groups of filaments adjacent each end of the bushing in FIG. 1 and their location in end view is shown in FIG. 2. Such couples can be adjusted to detect readily a 15F change in the operating range of temperatures and thus will respond with a significant signal within three seconds of a break out of glass fiber filament production when coupled to a suitable amplifier 33 through electrical leads 34. A power supply 35, advantageously of 12 volts direct current where solid state elements are employed in the amplifier, supplies the amplifier 33. Chromel-alumel is chosen as a suitable thermocouple for the temperature range encountered below a bushing from which glass fibers are produced, however, other such couples can be employed for glass filaments and appropriate changes can be made where different temperatures are present in the vicinity of the moving filaments. Since the amount of air aspirated andthus the degree of cooling varies with the speed of the filaments, amplifier 33 is arranged with suitable adjustments to accommodate the signal levels representative of the temperatures to be encountered. It is thus apparent thatv a change of filament speed can also be sensed and represented as a significant signal from sensor 32.

Signals from the thermocouples are at the millivolt level into amplifier 33 whose output can be a contact of a dry reed relay of either the normally open or normally closed variety. The output signal can be applied to an indicator or alarm 36, a counter (not shown), and/or an event recorder 38 coupled to the amplifier 33 through lead 37.

Where coordinated process monitoring is to be utilized, the winder programmer and control 25' can also be coupled to the event recorder 38 as through lead 39 to indicate the time relationship of shut-down and startup of the winder to the disruption of normal filament movement in the vicinity of the bushing tips 12. Similarly, the signal indicative of a disruption in filament motion from the normal can be employed to control the programmer 25 by passing it from lead 37 to lead 39 as a controlling function for stopping the winder.

It is to be understood that a number of utilizations of the detected change in filament motion are contemplated in addition to the noted alarm and/or event recorder operation. These include furnishing a signal to a computer which is programmed to compute the running efficiency of the bushing or providing a feedback control signal as to reduce bushing temperature while the winder is being doffed.

Alternative gas flow sensing devices can be employed to sense the flow of aspirated gas in the vicinity of moving filaments, particularly where the substantial temperature differentials of glass filament formation processes are not available in the region of filament motion to be monitored. In view of the variations which are suggested by the present invention, it is to be appreciated that the above description is to be read as illustrative of the invention and not in a limiting sense.

What I claim is:

1. In an apparatus for forming glass filaments wherein the glass filaments are drawn from orifices in a receptacle containing molten glass, the improvement comprising thermocouple means for sensing ambient temperature and issuing a signal in response to the sensed temperature, said thermocouple means being positioned within about one-eighth inch of both the filaments and the orifices whereby the ambient temperature and changes in the ambient temperature effected by motion of the filaments and breakage of the filaments are sensed; monitoring means responsive to the signal connected to said thermocouple means, said monitoring means comprising an amplifier connected to the thermocouple means for receiving signals from the thermocouple means which are indicative of the ambient temperature, the amplifier having adjustment means to ad just the amplifier to accommodate signal levels of temperatures to be encountered; and a control system for the apparatus which is connected to the amplifier.

2. A method for monitoring filament motion in a process wherein glass filaments are drawn from orifices of a receptacle containing molten glass comprising sensing ambient temperature by means of thermocouple means located within about one-eighth inch of both the filaments and the orifices of the receptacle whereby the ambient temperature and changes in the ambient temperature effected by motion of the filaments and breakage of the filaments are sensed; issuing a signal indicative of the ambient condition; and applying the signal to a control system for the apparatus.

3, A method for monitoring filament motion as defined in claim 2 comprising: maintaining the molten glass in the receptacle above 2,0(l0F., maintaining an air supply below 100F., and inducing a flow of the air supply when drawing the filaments by drawing the filaments from the orifices at speeds in excess of 5,000 feet per minute. 

1. In an apparatus for forming glass filaments wherein the glass filaments are drawn from orifices in a receptacle containing molten glass, the improvement comprising thermocouple means for sensing ambient temperature and issuing a signal in response to the sensed temperature, said thermocouple means being positioned within about one-eighth inch of both the filaments and the orifices whereby the ambient temperature and changes in the ambient temperature effected by motion of the filaments and breakage of the filaments are sensed; monitoring means responsive to the signal connected to said thermocouple means, said monitoring means comprising an amplifier connected to the thermocouple means for receiving signals from the thermocouple means which are indicative of the ambient temperature, the amplifier having adjustment means to adjust the amplifier to accommodate signal levels of temperatures to be encountered; and a control system for the apparatus which is connected to the amplifier.
 2. A method for monitoring filament motion in a process wherein glass filaments are drawn from orifices of a receptacle containing molten glass comprising sensing ambient tempErature by means of thermocouple means located within about one-eighth inch of both the filaments and the orifices of the receptacle whereby the ambient temperature and changes in the ambient temperature effected by motion of the filaments and breakage of the filaments are sensed; issuing a signal indicative of the ambient condition; and applying the signal to a control system for the apparatus.
 3. A method for monitoring filament motion as defined in claim 2 comprising: maintaining the molten glass in the receptacle above 2,000*F., maintaining an air supply below 100*F., and inducing a flow of the air supply when drawing the filaments by drawing the filaments from the orifices at speeds in excess of 5,000 feet per minute. 